... Hope to cooperate with you this time! Regarding 6mm diameter steel ball bearings , please find the details as follows:Item6mm ... bearingsBrandSKF,NSK,NTN,TIMKEN,KOYO,NACHI,FAG,INA,THKOriginCHINAMOQ1PCMaterialGood bearing steel, Carbon steelID6 mmCertificateISO9001:2000, ISO9001:2008Package1.Individual package, ... 3) Shield/closure: Z ZZ 2RS RS/open 4) Snap ring: N, NR 5) Tolerance codes: ABEC-1, ABEC-3 ...